1. Field of the Invention
This invention relates generally to vacuum cleaner filter bags and more particularly to a reinforced vacuum cleaner filter bag as well as a method of making same.
This invention relates to a disposable vacuum cleaner bag for use with top loading upright vacuum cleaners and a fully automated method for forming such bags.
2. Description of the Prior Art
Vacuum cleaner filter bags are typically formed from a blank which contains fold lines and cut-outs. The blank is folded on the specified lines and adhesive is applied during the course of the folding process whereby the filter bag is completed. Typically, such filter bags are folded into a tubular shape having closed ends with access means formed in the tubular bag for permitting passage of air into the interior of the bag so that air can be filtered.
The specific structure of the bag may vary depending upon the type of vacuum cleaner being utilized. For example, one typical filter bag is in the shape of a conventional page bag having a folded over edge on one end thereof and a bag bottom at the other end thereof. An opening is formed in the bag bottom which serves as the access means to permit the entry of air into the interior of the bag. The opening can then be connected to the vacuum cleaner outlet. Such a vacuum cleaner filter bag is described in U.S. Pat. No. 3,404,515.
With the aforementioned bag, a blank sheet material is formed with the appropriate fold lines and cut-outs. Adhesive is placed along the longitudinal edge to permit formation of an overlapped seam and the sheet is folded around to form a tubular structure. Then, the bottom is formed by appropriately folding the material. After the material is folded partway during the formation of the bottom, glue is applied in stripes and the material is then folded over to complete formation of the bottom. Transverse stripes of glue are then applied at the other end and the tubular material is folded onto itself to close off and seal the other end.
Another type of filter bag structure is the type having a long tubular body with both the upper and lower ends closed off by folding onto itself. An opening is formed in the tubular material and a separate connecting tube having an opening registered with the opening in the tubular body is connected. The connecting tube has its remote end available for connection to the vacuum cleaner outlet and the connecting tube serves as a passageway for the air into the filter bag.
This type of vacuum cleaner filter bag is described in U.S. Pat. No. 3,350,859 and wherein longitudinal fold lines are formed on the blank and the blank is folded around to form a tubular body having a front and rear panel and accordion side panels. Glue is provided in order to form an overlapping seam. Glue is also applied transversely at the upper and lower edges and the ends are then folded over onto itself to form a closed off cuff at the top and bottom portion. Adhesive is also placed around the registered openings to permit coupling of the connecting tube onto the tubular body. With both aforementioned types of vacuum cleaner filter bags, as well as with other types, although the filter bag is closed and appropriate adhesive is utilized for sealing and holding the bag closed, there is a tendency for rips and tears to occur at heavily stressed portions. Typically, tears will occur at the edges where the bag has been folded over in order to close off the bag. For example, at the folded over cuff portion, there will frequently occur tears or rips. Also, in the type of bag having a bottom, at the corners of the bottom, tears and rips tend to occur. Although additional adhesive can be applied, since the adhesive normally applied in stripes, it would necessitate applying a large amount of adhesive covering an excessive amount of area greater than the amount under stress. This would cause exposed adhesives which would be wet, tacky, and tend to stick to other adjacent bags during the course of processing.
Disposable vacuum cleaner bags have been made which are comprised of a tube portion which leads air and collected dust into another large air previous tube, or collection chamber. The tube portion may be made from an air pervious or air impervious material, while the collection chamber is of an air previous material. These bags are inserted into a cloth, vinyl, felt or other outer bag attached to a sweeper tank and, when full, the inner bag may be disposed of without dust problems associated with cleaners which do not use disposable bags.
Many upright cleaners which use such disposable bags are of a bottom loading design. Such bottom loading cleaners are disadvantageous in that the cleaner must force its air stream upwardly through previously collected dirt in the bag. In order to alleviate the problem, somewhat, with the bottom loading cleaners, vacuum cleaner bags have been developed which connect a transfer tube to the cleaner at a bottom connection, which transfer tube leads to a main collection bag compartment where the dirt is fed near the top and falls to the bottom of the collection compartment.
In U.S. Pat. No. 3,322,041, for example a bottom connection, but top loading design is shown, wherein the two sections are attached together only along the apertures which are formed in the two sections for passage of air flow from the transfer chamber to an air pervious or dust collection section. Such a design is an improvement over bottom loading design because a cleaner air stream does not have to flow through previously collected dirt. Prevalent top loading, but bottom connection, bag designs have a transfer tube which attaches to the dirt inlet duct of the vacuum cleaner near the bottom of the cleaner. The dirty air stream then blows up the transfer tube and through a window area between the transfer tube and the collection bag and then falls down into the collection bag. There are, however, two fundamental problems associated with such a bag design. One is that there is a tendency for the flexible duct member in the cleaner itself to collapse and cause clogging; and, secondly, it is possible for the consumer to improperly attach the bag to the cleaner. Indeed, this occurs often and results in bag failure and cleaner malfunction. The improper attachment occurs when the consumer folds the transfer tube into a U-shape before installing the bag, thus placing the bag, into the carrier, upside down.
In an attempt to overcome these problems associated with a bottom connection but top loading and top connection cleaners. Bags designed for use with such top loading cleaners overcame the above described problems, but also have caused problems of their own. Such bags require a transfer tube which attaches to the cleaner inlet duct and leads from the top of the bag to the cooperating apertures in the transfer tube and another section or collection bag. In order to produce the bags on fully automated equipment, the transfer tube must extend the full length of the collection bag. Since the window is near the top of the transfer tube, the entire lower section of the transfer tube would pack with dirt before dirt would flow through the window into the collection bag. In order to overcome this problem, the use of a short closed end bag or transfer tube was proposed, in combination with the collection bag, with the closed end bag having a hole in one wall communicating with the aperture in the wall of the collection bag. Use of such bags however, still left a small pocket below the windows which would fill with dirt. A further problem with such a short bag transfer tube collection bag combination, however, is that such a configuration requires three separate production operations. In one operation, the main bag body or collection bag is produced on one machine; in a second operation, the transfer tube or short bag section is produce and limits its availability.
The present invention relates to a method of manufacturing an outer bag for an upright vacuum cleaner on an automatic assembly line whereby bag material, as well as zipper material, both in continuous rolls are fed into an assembly line wherein zipper lengths are sewn on opposite sides of the bag material, and the assembled product is cut in predetermined lengths whereby the separated bag is zipped together to form a tube. The tube is enclosed at one or both ends to form a finished upright vacuum cleaner outer bag assembly.
The prior art method of manufacturing an outer bag is performed by either cutting the bag material to specified sizes and shapes, and attaching a finished assembled zipper to the sides of the cut panel by sewing or dielectric sealing means thereby forming a tube to be closed on one or both ends. Another method of manufacturing an outer bag for an upright vacuum cleaner is to cut the bag material into panels of specified sizes and shapes. Thereafter, one half of the zipper is attached to opposite sides of the panel by sewing or dielectric sealing methods. Then the sides with the zipper halves attached are zipped together causing the assembly to form a form a tube to be closed on one or both ends to form a bag.
Either of the above prior art methods of manufacturing an outer bag with a zipper for an upright vacuum cleaner is slow and time consuming. Consequently, the present invention, which automatically feeds both bag and zipper material in long rolls, whereby a high speed production of vacuum cleaner outer bags with zipper type openings is accomplished. The present method of manufacturing vacuum cleaner outer bags includes the use of a double headed sewing machine to sew the left and right side zippers thereon simultaneously. Thereafter, the assembled product is then fed into a cutting press with an automatic incremental feed system which cuts the bottom of one panel and the top of the succeeding panel to Specified lengths and constitutes a marked improvement over the methods practiced by the prior art.
Numerous innovations for the manufacture of vacuum cleaner bags have been provided in the prior art that are described as follows. Even though these innovations may be suitable for the specific individual purposes to which they address, they differ from the present invention as hereinafter contrasted.
U.S. Pat. No. 5,009,633 shows an method of manufacturing the outer cloth bag for an upright vacuum cleaner in which the bag material of a predetermined width is unwound from a reel and fed through guides, material folders and a double headed sewing machine. At the same time zipper chains are fed from rolls on the right and left side of the moving bag material. The zippers are sewn on opposite side edges of the bag, the bag material is cut into predetermined sized panels, and thereafter the side edges of the panels are folded and the zipper halves zipped up to form a tube. At least one open end is closed to form a bag.
U.S. Pat. No. 4,512,788 vacuum cleaner bag for use with top loading vacuum cleaner has a first collection tube and a second transfer tube, the tubes having communicating apertures near the top thereof, with a thermoplastic coating on the inner walls of the second transfer tube which is fused together to seal the second transfer tube adjacent the lower wall of the aperture thereof, the top and bottom of the first tube and bottom of the second transfer tube adhesively sealed; and method for automatically forming the bags by superimposing the two tubes, adhesively securing them together, heat sealing the inner walls of the second transfer tube together, below the aperture, and closing the ends of the tubes.
U.S. Pat. No. 4,322,259 shows a vacuum cleaner filter bag formed from a blank including a sheet of air permeable filter paper, and which is folded to define a tubular container having closed ends with an access opening formed in the container for permitting the passage of air into the interior of the bag so that the air can be filtered. The bag is formed by folding the blank and applying adhesive material onto specific areas during the folding operation in order to form the bag. On the blank itself there is also pre-applied, by pre-printing or extruding, a heat, self-stick or pressure sensitive type of adhesive material on specified areas, these areas being susceptible to tears. After the bag is formed, it is passed through a heat or pressure applying station which activates the pre-printed or extruded adhesive material thereby providing reinforcement to the bag at the areas which tend to tear.
U.S. Pat. No. 3,848,813 discloses a system in which urban waste, such as that collected from households in urban areas, is processed in the dry "as collected" state to recover ferrous metals, nonferrous metals, glass and paper fractions of suitable quality for sale and recycling. Waste is first shredded without balling or crushing tin cans and is thereafter subjected to a series of separations based upon differences in the physical properties of the waste materials.
U.S. Pat. No. 5,078,668 discloses is a method of making garment protector that is of high quality, having an envelope structure made of cloth fabric with an easy access opening in one of its sides covered by a flap member.
U.S. Pat. No. 4,322,259 discloses a vacuum cleaner filter bag formed from a blank including a sheet of air permeable filter paper, and which is folded to define a tubular container having closed ends with an access opening formed in the container for permitting the passage of air into the interior of the bag so that the air can be filtered. The bag is formed by folding the blank and applying adhesive material onto specific areas during the folding operation in order to form the bag. On the blank itself there is also pre-applied, by pre-printing or extruding, a heat, self-stick or pressure sensitive type of adhesive material on specified areas, these areas being susceptible to tears. After the bag is formed, it is passed through a heat or pressure applying station which activates the pre-printed or extruded adhesive material thereby providing reinforcement to the bag at the areas which tend to tear.
Numerous innovations for the manufacture of vacuum cleaner bags have been provided in the prior art that are adapted to be used. Even though these innovations may be suitable for the specific individual purposes to which they address, they would not be suitable for the purposes of the present invention as heretofore described.